Prince Said Halim's Palace or (wrongly known as) Champollion House, Cairo, Egypt. This residence was designed by Antonio Lasciac in Later, it was converted to one of the best secondary schools for boys (Al-Nassiriyah) in the country.
Muromtzevo Castle Mansion, Russia - Russian architect P. Boitzov built many French style "medieval" castles in the century, but Muromtzevo is the most spectacular - This old photo shows it in its glory days.
This mansion was built between 1853 and 1855 by a banker named Edward Lloyd. After World War I, the house was sold and became a public school for girls. It closed in and the building has been abandoned since then. (via Ghost Of, and nellyurbex)